Independent review. IonBin has no partnership with Firstbase and was not paid for this page. Our evaluation is our own, based on public documentation and our research. Product names are trademarks of their owners and are used for identification only. How disclosure works.
Incorporation (Delaware or Wyoming), registered agent, compliance, mailroom, accounting and tax filing for startups. No MCP server is documented; a partner Incorporation API exists for platforms. Requirements vary by state; check official filings yourself.
IonBin provides general information and software comparisons, not tax, legal, accounting or financial advice. Tax and legal rules vary by situation and jurisdiction; consult a qualified professional (CPA, enrolled agent or attorney) before acting.
AI tools can make mistakes. Verify every figure against the original documents and official IRS or state guidance before filing or signing.
Redact Social Security numbers, account numbers and EINs before uploading documents to any AI assistant, and check its data-retention settings. Upload originals only to the filing or signing software.
Requirements vary by state. File through official sources such as the USPTO trademark search and your state’s Secretary of State site.
Firstbase Start (formation in Delaware or Wyoming, EIN setup, core documents) was $99 one-time during an offer (regular $399), plus state fee. Firstbase One is $199/month billed yearly at $2,388. Add-ons include Mailroom Premium ($350), Registered Agent ($299), Accounting ($1,890) and Tax Filing ($1,799). Checked 2026-10-17. source ↗
How Firstbase connects to each AI platform: native connector or MCP, API through code the agent writes, browser control, or file upload.
| Platform | MCP / connector | API (agent-written code) | Browser | Upload / export |
|---|---|---|---|---|
| Claude (incl. Claude Code) | No documented route | Confirmed Claude (incl. Claude Code) can run code; Firstbase publishes an API. Claude (incl. Claude Code) docs ↗ | Confirmed Claude Code with the Claude in Chrome extension (Chrome, Edge and other Chromium browsers) Claude (incl. Claude Code) browser docs ↗ | Confirmed Export from Firstbase, then works on the files in your project; chat accepts attachments Claude (incl. Claude Code) docs ↗ |
| OpenAI Codex | No documented route | Confirmed OpenAI Codex can run code; Firstbase publishes an API. OpenAI Codex docs ↗ | Confirmed Only in the ChatGPT desktop app; not in the Codex CLI or IDE extension OpenAI Codex browser docs ↗ | Confirmed Export from Firstbase, then works on local repositories OpenAI Codex docs ↗ |
| Google Antigravity | No documented route | Confirmed Google Antigravity can run code; Firstbase publishes an API. Google Antigravity docs ↗ | Confirmed Browser subagent via /browser, documented as an Antigravity App feature; the IDE has separate browser docs Google Antigravity browser docs ↗ | Confirmed Export from Firstbase, then works on local projects and worktrees Google Antigravity docs ↗ |
Confirmed means both the tool's and the platform's official docs describe that route (links in the cell); IonBin has not tested every pairing. Not documented means it may work, but no official docs describe that route end to end. Checked Oct 17, 2026.
| Level | Status | Detail / source |
|---|---|---|
| Native connector / MCP | No | — |
| API / CLI | Yes | Incorporation API for partners (https://www.firstbase.io/referral-partner-program) |
| Browser-only | No | Web app; also reachable programmatically |
| Bulk upload / import | No | — |
Recorded Oct 17, 2026. Setup and plan limits vary; check the vendor's docs. How levels are assigned.
No confirmed MCP server yet.
Via its API, through automation hubs: Gumloop, Make, n8n, Zapier.
No long-form review yet. Verdict is based on research, not hands-on testing.
US company formation for founders anywhere, with compliance, bookkeeping and tax add-ons. Its MCP server lets an AI agent run a Wyoming LLC formation; filing is irreversible. Requirements vary by state; treat AI output as research notes, not advice.
Registered-agent and company-formation service. Its MCP server lets AI clients look up your companies, filings and invoices and pay invoices after sign-in. Requirements vary by state; check your Secretary of State before filing. Not legal advice.
